Conversion of dimethyl ether to toluene under an O2 stream over W/HZSM-5 catalysts

Abstract

The direct conversion of dimethyl ether (DME) to toluene without other aromatics is realized over W/HZSM-5 catalysts with high W contents. The influence of W content on the nature of tungsten species, the distribution of acid sites, the redox properties, and the subsequent catalytic performance of W/HZSM-5 in DME conversion was investigated. The introduction of a high content of W in HZSM-5 can bring about some new redox sites and acidic sites associated with W species, although they also cover some acidic sites in HZSM-5. In this way, the introduction of W interrupts the dual cycle of the DME-to-hydrocarbon reaction on HZSM-5, and effectively the formation of higher methylbenzenes is limited.